1. Field of the Invention
The present invention relates to a liquid crystal display having a curved display surface.
2. Description of the Background Art
A transmission type liquid crystal display in the background art consists of a liquid crystal panel in which fluid liquid crystal is sealed between a pair of flat glass substrates and polarizing plates are disposed on respective external surfaces of the glass substrates and a backlight, which are stacked, and its display surface is flat. By using a flexible substrate having a thickness of 0.3 mm or less, such as a thin glass substrate, a plastic film or the like, in this transmission type liquid crystal display, a liquid crystal display having a curved display surface can be achieved. Such a liquid crystal display having a curved display surface has a great degree of freedom in design and achieves excellent functions in practical utility. If the display surface has a particular curved form, for example, it is possible to effectively suppress reflection of extraneous light (see, e.g., Japanese Patent Application Laid Open Gazette No. 6-3650).
In manufacturing a liquid crystal display using thin glass substrates, in order to keep the pattern accuracy of various microstructures formed on surfaces of the substrates and ensure easy handling in transfer or the like, thick glass substrates are used till halfway in the manufacturing process, and the two glass substrates are pasted together and then thinned by etching or polishing (see, e.g., Japanese Patent Application Laid Open Gazette No. 2005-128411).
In such a case as above where flat glass substrates are pasted together and then thinned and curved, disadvantageously, luminance unevenness occurs in displaying an image and display unevenness thereby occurs. This is caused by the fact that the curvatures of the two glass substrates vary by almost the thicknesses of the substrates and the relative positions of pixel structures arranged on these substrates become misaligned in the curve direction. Such positional misalignment is caused not only in the case where thin glass substrates are used but also in the case where plastic films are used as substrates, when flat substrates are pasted together and then curved.
Another method of manufacturing a liquid crystal display using flexible thin glass substrates is proposed, where a wall structure of resin is formed in a liquid crystal layer and two substrates are bonded by the wall structure, to suppress the positional misalignment (see, e.g., Japanese Patent Application Laid Open Gazette No. 2004-219769). In the method disclosed in the above Patent Document, since a photocurable resin is mixed into liquid crystal and the wall structure and the substrates are bonded by light emission, uncured components are sometimes left in the liquid crystal as impurities. When the uncured components are left in the liquid crystal as impurities, it disadvantageously becomes easier to cause display failures such as burn-in and the like.
Still another method is proposed, where pixel structures such as color filters, black matrixes and the like which are usually formed on a counter substrate are formed on the side of an array substrate (see, e.g., Japanese Patent Application Laid Open Gazette No. 2007-94102). In such a method, however, since a process of manufacturing color filters, black matrixes and the like is added to the process of manufacturing the array substrate, though these processes are usually performed concurrently, the time period required to manufacture the whole liquid crystal display disadvantageously becomes longer.